package cn.tedu.sp11.fallback;

import cn.tedu.web.util.JsonResult;
import org.springframework.cloud.netflix.zuul.filters.route.FallbackProvider;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.stereotype.Component;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.StandardCharsets;

@Component
public class ItemFB implements FallbackProvider {
    /*
    * 设置当前降级类，针对哪个服务降级
    * Item-service：只对商品降级
    * "*":所有服务都应用当前降级类
    * null:所有服务都应用当前降级类
    * */
    @Override
    public String getRoute() {
        return "item-service";
    }
    /*向客户端发送降级响应 */
    @Override
    public ClientHttpResponse fallbackResponse(String route, Throwable cause) {
        return new ClientHttpResponse() {
            @Override
            public HttpStatus getStatusCode() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR;
            }

            @Override
            public int getRawStatusCode() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR.value();
            }

            @Override
            public String getStatusText() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR.getReasonPhrase();
            }

            @Override
            public void close() {
                //在响应执行结束后，关闭输入流

                //对于BAIS来说：jvm内存中的流，不占用任何系统资源，所以不需要关闭
            }

            @Override
            public InputStream getBody() throws IOException {
                String json=JsonResult.err().code(500).msg("调用商品服务失败").toString();
                return new ByteArrayInputStream(json.getBytes(StandardCharsets.UTF_8));
            }

            @Override
            public HttpHeaders getHeaders() {
                HttpHeaders h=new HttpHeaders();
                h.add("Content-Type", "application/json;charset=utf-8");
                return  h;
            }
        };
    }
}
